阅读说明：本技术 一种热喷涂Ni基合金自润滑涂层的制备方法 (Preparation method of thermal spraying Ni-based alloy self-lubricating coating ) 是由 卢金斌 孟雯露 徐洪洋 秦艳芳 申刚 常婕 于 2020-12-03 设计创作，主要内容包括：本发明公开了一种热喷涂Ni基合金自润滑涂层的制备方法,采用等离子喷涂设备在低碳钢表面喷涂由一定比例的Ni-Cr-B-Si合金粉、Ti粉、镍包Ti-3SiC-2粉组成的混合粉末,虽Ti-3SiC-2具有较好稳定性,为进一步避免在喷涂热作用过程中分解,确保其良好的自润滑性能,在喷涂前对Ti-3SiC-2进行了镀镍处理,经喷涂后制备了含有一定量Ti-3SiC-2的Ni基涂层,由于Ni基合金对Ti-3SiC-2的良好润湿,使得涂层致密、空隙率小,并且Ti-3SiC-2保持较好,其良好的润滑性提高了涂层的润滑性,制备的涂层具有耐磨性高、减磨的优点。(The invention discloses a preparation method of a thermal spraying Ni-based alloy self-lubricating coating, which adopts plasma spraying equipment to spray Ni-Cr-B-Si alloy powder, Ti powder and nickel-coated Ti powder with a certain proportion on the surface of low-carbon steel 3 SiC 2 Mixed powder of powders, albeit Ti 3 SiC 2 Has good stability, and can further avoid the thermal effect in sprayingDecomposing in the process to ensure good self-lubricating property, and spraying Ti 3 SiC 2 Nickel plating treatment is carried out, and a certain amount of Ti is prepared after spraying 3 SiC 2 Due to the Ni-based alloy to Ti 3 SiC 2 Good wetting, compact coating, low porosity, and Ti 3 SiC 2 The lubricating property of the coating is improved due to the good lubricating property of the coating, and the prepared coating has the advantages of high wear resistance and wear reduction.)

1. A preparation method of a thermal spraying Ni-based alloy self-lubricating coating is characterized in that self-lubricating components are added into spraying powder, and the prepared coating has the characteristics of friction reduction and wear resistance, and the preparation method comprises the following process steps:

step one, Ni-Cr-B-Si alloy powder, Ti powder and nickel-coated Ti₃SiC₂Mixing the powder according to a certain proportion, and ball-milling and mixing the powder by using a ball mill to prepare spraying powder, wherein the particle size of the prepared powder is 25-60 mu m;

selecting the surface of a carbon steel workpiece to be strengthened as a matrix, removing rust and oil stains on the surface of the workpiece, then carrying out sand blasting treatment, coarsening the surface of the workpiece, and finally preheating the surface of the workpiece by adopting an external heating mode;

thirdly, pre-spraying a Ni-Al bonding layer on the surface of the workpiece in a thermal spraying mode;

and step four, heating the mixed spraying powder according to certain spraying process parameters by adopting plasma thermal spraying equipment, thermally spraying the surface of the workpiece, and cooling to obtain the wear-resistant coating.

2. The method for preparing the thermal spraying Ni-based alloy self-lubricating coating according to claim 1, wherein the method comprises the following steps: the Ni-Cr-B-Si alloy powder, the Ti powder and the nickel-coated Ti₃SiC₂The mass ratio of the powder is 78-87: 3-7: 10-15; the Ni-Cr-B-Si alloy powder comprises the following components in percentage by mass: 16-18%, B: 2.5-4.5%, Si: 3-4.5%, C: 0.8-1.1% of Ni; in addition, the purity of Ti is higher than 99.5%, and the particle size is 30-60 μm;ni coated Ti₃SiC₂Has a particle size of 50-75 μm, wherein the weight content of nickel is 12-15%, and the balance is Ti₃SiC₂。

3. The method for preparing the thermal spraying Ni-based alloy self-lubricating coating according to claim 1, wherein the method comprises the following steps: the ball milling mixing is carried out by adopting a steel ball milling tank, wherein the mass ratio of milling balls to metal powder is 2.6-3.1: 1, a vacuum valve is opened after sealing, vacuum pumping is carried out for 25-35 minutes, the ball milling tank is placed into a planetary ball mill, the rotating speed is 270-320 r/min, the inversion frequency is 30-45 Hz, and the ball milling mixing time is 60-80 minutes.

4. The method for preparing the thermal spraying Ni-based alloy self-lubricating coating according to claim 1, wherein the method comprises the following steps: and preheating, wherein the temperature of the preheating is controlled to be 250-300 ℃.

5. The preparation method of the thermal spraying Ni-based alloy self-lubricating coating according to claim 1, characterized in that the Ni-Al bonding layer uses Ni-Al alloy powder with the granularity of 85-150 μm, the mass of Al is 9-18%, the rest is Ni, and the thickness of the bonding layer is controlled to be 30-100 μm.

6. The method for preparing the thermal spraying Ni-based alloy self-lubricating coating according to claim 1, wherein the certain spraying process parameters are as follows: the spraying distance is 90-120mm, the working current is 520-650A, the working voltage is 50-70V, the Ar gas speed is 30-50L/min, H₂The speed is 5-10 liters/min, the powder feeding amount is 38-45g/min, the cooling gas pressure is 0.3-0.5MPa, and the moving speed of a spray gun is as follows: 30-80 mm/s.

Technical Field

The invention belongs to the field of high-energy beam surface treatment, and particularly relates to a method for preparing a wear-resistant antifriction composite coating by adopting surface thermal spraying aiming at low-carbon steel.

Background

Mechanical devices are of a wide variety, and some components typically undergo different forms of mechanical movement while they are in operation. The parts move relative to other substances to generate friction in the using process, so that not only can a large amount of heat be generated, but also the parts are worn to different degrees and even early failure is caused, and therefore, higher requirements on the surface wear resistance and the wear reduction performance of the parts are provided. The low-carbon steel has better plasticity and toughness, good welding performance and cold forming performance, can be subjected to cold forming by adopting various stamping methods, and is widely applied, but the application of the low-carbon steel is limited to a certain extent due to lower surface hardness and poor wear resistance. The wear-resistant coating is prepared on the surface of a part, so that the wear resistance of parts can be improved, the service life of mechanical equipment is prolonged, the reliability of the mechanical equipment is improved, the surface of a mating part can be damaged by simply improving the wear resistance sometimes, the wear of the mating part is aggravated, lubrication is needed sometimes to reduce friction, and the effect of common lubricating oil is not good under working conditions such as high temperature, heavy load, vacuum and radiation. One of the effective methods is to prepare a coating on the surface of a part to reduce friction and improve wear resistance. The metal-based self-lubricating coating has good performances of wear resistance, lubrication, high temperature resistance and the like, but the type, the amount and the combination condition of the lubricant and a matrix influence the strength and the toughness of the coating to a certain extent, and if defects such as large cracks, holes and the like occur, the mechanical property of the part can be greatly reduced.

The self-fluxing alloy powder Ni-Cr-B-Si is usually smelted and atomized into powder by water (or gas), wherein boron and silicon can reduce the melting point of the alloy and play a role in slagging so as to avoid oxidation, and chromium in the self-fluxing alloy powder generates chromium carbideAnd the chromium boride hard phase is dispersed in the nickel matrix, so that the alloy powder has the properties of high hardness, high wear resistance, corrosion resistance and the like, is particularly suitable for preparing coatings, and is widely applied to material engineering. The Ni-Cr-B-Si can be sprayed to prepare a wear-resistant coating, so that the wear resistance of parts can be improved, but the high hardness of the coating can aggravate the wear of mating parts on certain occasions, particularly how to improve the lubricating property of the coating under the condition that lubricating oil cannot be adopted, and the problems of temperature rise, wear aggravation of the mating parts and the like caused by friction are solved. Ternary compound Ti₃SiC₂The microstructure of (a) is a Ti layer shared by two edges connected by a two-dimensional closed filled Si layer₆A C octahedral layer structure with a special structure such that Ti₃SiC₂Has better high-temperature performance, good thermal conductivity and high thermal stability, the layered structure of the material ensures that the material has lower friction coefficient and better self-lubricating property than graphite, and Ti is sprayed in the spraying process₃SiC₂The lubricating performance of the coating can be improved by adding the lubricating agent into the coating, but the high temperature such as plasma arc, flame and the like can cause the coating to be decomposed and lose the lubricating effect, so that the lubricating agent can be used for Ti₃SiC₂Nickel plating treatment is carried out to avoid high-temperature decomposition, and the Ni-based self-fluxing alloy can not only be used for plating nickel Ti₃SiC₂Good wetting, addition of Ti by thermal spraying₃SiC₂The obtained Ni-based coating has the characteristics of wear resistance and friction reduction.

Disclosure of Invention

The invention designs that nickel-plated Ti is added into Ni-Cr-B-Si self-fluxing alloy powder₃SiC₂The coating is sprayed on the surface of carbon steel as a self-lubricating component, has certain lubricity, can reduce friction during working and high temperature generated by the friction, and is particularly suitable for being used under the condition that lubricating oil cannot be used. The coating preparation process has the advantages of simple powder preparation and low cost.

The manufacturing method for solving the technical problem comprises the following process steps:

step one, Ni-Cr-B-Si alloy powder, Ti powder and nickel-coated Ti₃SiC₂The powder is mixed according to the mass ratio of 78-87: 3-7: 10 to 15 by weightBall milling and mixing by a ball mill to prepare spraying powder, wherein the particle size of the prepared powder is 25-60 mu m; wherein the mass content of the Ni-Cr-B-Si component is Cr: 16-18%, B: 2.5-4.5%, Si: 3-4.5%, C: 0.8-1.1% of Ni; in addition, the purity of the Ti powder is higher than 99.5%, and the particle size is 30-60 mu m; ni coated Ti₃SiC₂Has a particle size of 50-75 μm, wherein the weight content of nickel is 12-15%, and the balance is Ti₃SiC₂. Ball milling and mixing are carried out by adopting a steel ball milling tank, wherein the mass ratio of grinding balls to metal powder is 2.6-3.1: 1, a vacuum valve is opened after sealing, vacuum pumping is carried out for 25-35 minutes, the ball milling tank is placed into a planetary ball mill, the rotating speed is 270-320 r/min, the inversion frequency is 30-45 Hz, and ball milling and mixing are carried out for 60-80 minutes.

Selecting the surface of a carbon steel workpiece to be strengthened as a matrix, removing rust and oil stains on the surface of the workpiece, then carrying out sand blasting treatment on the surface of the workpiece to coarsen the surface of the workpiece, and finally preheating the surface of the workpiece by adopting an external heating mode, wherein the preheating temperature is controlled to be 250-300 ℃.

And thirdly, pre-spraying a Ni-Al bonding layer on the surface of the workpiece by adopting a thermal spraying mode, wherein the granularity of the Ni-Al alloy powder is 85-150 mu m, the mass of Al is 9-18%, the balance is Ni, and the thickness of the bonding layer is controlled to be 30-100 mu m.

Heating the mixed spraying powder by adopting plasma thermal spraying equipment according to certain spraying process parameters to thermally spray the surface of the workpiece, and cooling to obtain the wear-resistant coating, wherein the spraying process parameters are as follows: the spraying distance is 90-120mm, the working current is 520-650A, the working voltage is 50-70V, the Ar gas speed is 30-50L/min, H₂The speed is 5-10 liters/min, the powder feeding amount is 38-45g/min, the cooling gas pressure is 0.3-0.5MPa, and the moving speed of the spray gun is 30-80 mm/s.

The invention has the beneficial effects that:

(1) the coating sprayed by the invention contains Ti with good high-temperature and self-lubricating properties₃SiC₂Can reduce the friction of the coating during operation, and further reduce the high temperature generated by the friction, and in addition, Ti₃SiC₂Better thermal conductivity may also further reduce the coating to some extentHigh temperature of (2).

(2) The Ni-based alloy is adopted as the substrate of the coating, has good high-temperature performance, toughness and wear resistance, and can improve the wear resistance of the coating.

(3) Nickel coated Ti added to coatings₃SiC₂After nickel plating, certain Ti element is contained in the spraying powder to ensure that Ti is formed₃SiC₂Has better stability in the high-temperature spraying process and finally keeps Ti₃SiC₂Good lubricating performance.

Detailed Description

The present invention will be described in detail below with reference to various embodiments. The embodiments are not intended to limit the present invention, and structural, methodological, or functional changes made by those skilled in the art according to the embodiments are included in the scope of the present invention.

Example 1:

step one, Ni-Cr-B-Si alloy powder, Ti powder and nickel-coated Ti₃SiC₂The powder is prepared from the following components in percentage by mass: 7: 15, and ball-milling and mixing the mixture by using a ball mill to prepare spraying powder, wherein the particle size of the prepared powder is 25-60 mu m; wherein the mass content of the Ni-Cr-B-Si component is Cr: 16-18%, B: 2.5-4.5%, Si: 3-4.5%, C: 0.8-1.1% of Ni; in addition, the purity of the Ti powder is higher than 99.5%, and the particle size is 30-60 mu m; ni coated Ti₃SiC₂Has a particle size of 50-75 μm, wherein the weight content of nickel is 12-15%, and the balance is Ti₃SiC₂. The ball milling and mixing are carried out by adopting a steel ball milling tank, wherein the mass ratio of the milling balls to the metal powder is 2.6: 1, the vacuum valve is opened after the sealing, the vacuum pumping is carried out for 25 minutes, the ball milling tank is placed into a planetary ball mill, the rotating speed is 270r/min, the inversion frequency is 30Hz, and the ball milling and mixing time is 60 minutes.

Selecting Q235 steel as a matrix, removing rust and oil stains on the surface of the workpiece, then carrying out sand blasting treatment on the surface of the workpiece to coarsen the surface of the workpiece, and finally preheating the surface of the workpiece by adopting an external heating mode, wherein the preheating temperature is controlled at 250 ℃.

And thirdly, pre-spraying a Ni-Al bonding layer on the surface of the workpiece by adopting a thermal spraying mode, wherein the granularity of the used Ni-Al alloy powder is 85-150 mu m, the mass of Al is 9 percent, the balance is Ni, and the thickness of the bonding layer is controlled to be 30 mu m.

Heating the mixed spraying powder by adopting plasma thermal spraying equipment according to certain spraying process parameters to thermally spray the surface of the workpiece, and cooling to obtain the wear-resistant coating, wherein the spraying process parameters are as follows: the spraying distance is 90mm, the working current is 520A, the working voltage is 50V, the Ar gas speed is 30 liters/min, and H is₂The speed is 5 liters/min, the powder feeding amount is 38g/min, the cooling gas pressure is 0.3MPa, and the moving speed of the spray gun is 30 mm/s.

Experiments show that the coating after the plasma thermal spraying is basically compact and has no air holes, the coating structure is distributed in a layered manner, is basically smooth and has no cracks and cavities, and the coating structure mainly comprises nickel-based solid solution and Ti₃SiC₂And after the carbide of Cr and a sample of GCr15 are ground, a lubricating film is formed on the surface of the coating, which is favorable for reducing friction, and the carbide and boride in the coating are favorable for improving wear resistance.

Example 2:

step one, Ni-Cr-B-Si alloy powder, Ti powder and nickel-coated Ti₃SiC₂The powder is prepared from 87 mass percent: 7: 15, ball-milling and mixing to prepare spraying powder, wherein the particle size of the prepared powder is 25-60 mu m; wherein the mass content of the Ni-Cr-B-Si component is Cr: 16-18%, B: 2.5-4.5%, Si: 3-4.5%, C: 0.8-1.1% of Ni; in addition, the purity of the Ti powder is higher than 99.5%, and the particle size is 30-60 mu m; ni coated Ti₃SiC₂Has a particle size of 50-75 μm, wherein the weight content of nickel is 12-15%, and the balance is Ti₃SiC₂. The ball milling and mixing are carried out by adopting a steel ball milling tank, wherein the mass ratio of the milling balls to the metal powder is 3.1: 1, the vacuum valve is opened to vacuumize for 35 minutes after the sealing, the ball milling tank is placed into a planetary ball mill, the rotating speed is 320r/min, the inversion frequency is 45Hz, and the ball milling and mixing time is 80 minutes.

And step two, removing rust and oil stains on the surface of a Q345 steel workpiece, then carrying out sand blasting treatment on the surface of the roughened workpiece, and finally preheating the surface of the workpiece by adopting an external heating mode, wherein the preheating temperature is controlled at 300 ℃.

And thirdly, pre-spraying a Ni-Al bonding layer on the surface of the workpiece by adopting a thermal spraying mode, wherein the granularity of the used Ni-Al alloy powder is 85-150 mu m, the mass of Al is 18 percent, the balance is Ni, and the thickness of the bonding layer is controlled to be 100 mu m.

Heating the mixed spraying powder by adopting plasma thermal spraying equipment according to certain spraying process parameters to thermally spray the surface of the workpiece, and cooling to obtain the wear-resistant coating, wherein the spraying process parameters are as follows: the spraying distance is 120mm, the working current is 650A, the working voltage is 70V, the Ar gas speed is 50 liters/min, and H is₂The speed is 10 liters/min, the powder feeding amount is 45g/min, the cooling gas pressure is 0.5MPa, and the moving speed of a spray gun is as follows: 80 mm/s.

Experiments show that the plasma thermal spraying process has strong adaptability, the prepared coating is basically compact and has no air holes, the deformation of a workpiece is small, the metallographic structure and the performance of the metallographic structure are not changed, the coating structure is distributed in a layered mode and is smooth, cracks and cavities do not exist, and the coating structure mainly comprises nickel-based solid solution and Ti₃SiC₂And after the carbide of Cr and a sample of GCr15 are subjected to opposite grinding, a lubricating film can be formed on the surface of the coating, the friction of the prepared coating is reduced, and the wear resistance of the matrix is improved, but the wear resistance is required to be further improved under the conditions of stronger corrosion, heavy load and the like.

Example 3:

step one, Ni-Cr-B-Si alloy powder, Ti powder and nickel-coated Ti₃SiC₂The powder is prepared from the following components in percentage by mass: 5: 12, and ball-milling and mixing the mixture by using a ball mill to prepare spraying powder, wherein the particle size of the prepared powder is 25-60 mu m; wherein the mass content of the Ni-Cr-B-Si component is Cr: 16-18%, B: 2.5-4.5%, Si: 3-4.5%, C: 0.8-1.1% of Ni; in addition, the purity of the Ti powder is higher than 99.5%, and the particle size is 30-60 mu m; ni coated Ti₃SiC₂Has a particle size of 50-75 μm, wherein the weight content of nickel is 12-15%, and the balance is Ti₃SiC₂. Ball milling and mixing are carried out by adopting a steel ball milling tank, wherein the mass ratio of the milling balls to the metal powder is 2.8: 1, the vacuum valve is opened after sealing, the vacuum pump is vacuumized for 30 minutes, the ball milling tank is placed into a planetary ball mill, the rotating speed is 290r/min, and the inversion frequency is higher thanAnd the ball milling and mixing time is 70 minutes at 38 Hz.

Selecting the surface of a Q195 steel workpiece to be strengthened as a matrix, removing rust and oil stains on the surface of the workpiece, then carrying out sand blasting treatment on the surface of the roughened workpiece, and finally preheating the surface of the workpiece by adopting an external heating mode, wherein the preheating temperature is controlled at 270 ℃.

And thirdly, pre-spraying a Ni-Al bonding layer on the surface of the workpiece by adopting a thermal spraying mode, wherein the granularity of the used Ni-Al alloy powder is 85-150 mu m, the mass of Al is 12%, the balance is Ni, and the thickness of the bonding layer is controlled to be 60 mu m.

Heating the mixed spraying powder by adopting plasma thermal spraying equipment according to certain spraying process parameters to thermally spray the surface of the workpiece, and cooling to obtain the wear-resistant coating, wherein the spraying process parameters are as follows: the spraying distance is 108mm, the working current is 580A, the working voltage is 60V, the Ar gas speed is 40L/min, and H is₂The speed is 8 liters/min, the powder feeding amount is 40g/min, the cooling gas pressure is 0.4MPa, and the moving speed of the spray gun is as follows: 50 mm/s.

Experiments show that the coating after the plasma thermal spraying is compact and has no obvious air holes, the sprayed layer is stacked together in a wave form by crossing numerous deformed particles, basically has a layered structure, has a basically smooth structure and has no cracks and cavities, and the coating structure mainly comprises nickel-based solid solution and Ti₃SiC₂And Cr carbide is subjected to opposite grinding with a sample of GCr15, and a lubricating film is formed on the surface of the coating, so that the friction is reduced, and the wear resistance of the matrix is improved.

Example 4:

step one, Ni-Cr-B-Si alloy powder, Ti powder and nickel-coated Ti₃SiC₂The powder is prepared from the following components in percentage by mass: 7: 12, and ball-milling and mixing the mixture by using a ball mill to prepare spraying powder, wherein the particle size of the prepared powder is 25-60 mu m; wherein the mass content of the Ni-Cr-B-Si component is Cr: 16-18%, B: 2.5-4.5%, Si: 3-4.5%, C: 0.8-1.1% of Ni; in addition, the purity of Ti is higher than 99.5%, and the particle size is 30-60 μm; ni coated Ti₃SiC₂Has a particle size of 50-75 μm, wherein the weight content of nickel is 12-15%, and the balance is Ti₃SiC₂. The ball milling and mixing are performed by adopting a steel ball milling tankBall milling and mixing are carried out, wherein the mass ratio of the grinding balls to the metal powder is 3: 1, a vacuum valve is opened after sealing, vacuum pumping is carried out for 30 minutes, the ball milling tank is placed into a planetary ball mill, the rotating speed is 300r/min, the inversion frequency is 40Hz, and the ball milling and mixing time is 70 minutes.

Selecting the surface of a Q195 steel workpiece to be strengthened as a matrix, removing rust and oil stains on the surface of the workpiece, performing sand blasting treatment, roughening the surface of the workpiece, and finally preheating the surface of the workpiece by adopting an external heating mode, wherein the preheating temperature is controlled at 270 ℃.

And thirdly, pre-spraying a Ni-Al bonding layer on the surface of the workpiece by adopting a thermal spraying mode, wherein the granularity of the used Ni-Al alloy powder is 85-150 mu m, the mass of Al is 15%, the balance is Ni, and the thickness of the bonding layer is controlled to be 60 mu m.

Heating the mixed spraying powder by adopting plasma thermal spraying equipment according to certain spraying process parameters to thermally spray the surface of the workpiece, and cooling to obtain the wear-resistant coating, wherein the spraying process parameters are as follows: the spraying distance is 95mm, the working current is 600A, the working voltage is 60V, the Ar gas speed is 40L/min, and H is₂The speed is 7 liters/min, the powder feeding amount is 39g/min, the cooling gas pressure is 0.4MPa, and the moving speed of the spray gun is as follows: 50 mm/s.

Experiments show that the coating after the plasma thermal spraying is compact and has no obvious air holes, the sprayed layer is stacked together in a wave form by crossing numerous deformed particles, basically has a layered structure, has a basically smooth structure and has no cracks and cavities, and the coating structure mainly comprises nickel-based solid solution and Ti₃SiC₂And the carbide of Cr is subjected to opposite grinding with a sample of GCr15, so that a lubricating film can be formed on the surface of the coating, the friction is reduced, and the wear resistance of the matrix is improved.

It will be evident to those skilled in the art that the invention is not limited to the details of the foregoing illustrative embodiments, and that the present invention may be embodied in other specific forms without departing from the spirit or essential attributes thereof. The present embodiments are therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein.

Furthermore, it should be understood that although the present description refers to embodiments, not every embodiment may contain only a single embodiment, and such description is for clarity only, and those skilled in the art should integrate the description, and the embodiments may be combined as appropriate to form other embodiments understood by those skilled in the art.